The invention relates to a truck having a cabin on which air aerodynamic roof deflector panel is mounted. The invention also relates to a method for controlling such a truck.
When trucks are stopped on parking areas with their engine stopped, the main air conditioning system of these trucks does not operate. Some trucks have auxiliary air conditioning systems. Such auxiliary systems are not efficient enough in case the truck is parked in direct sunshine in summer time. Consequently, the cabin of the truck can reach uncomfortable temperatures for the driver, who may wish to rest in his cabin.
Generally, trucks are equipped with a roof wind deflector adapted to reduce air drag produced by the height difference between the roof of the cabin and the top of the transport compartment or the trailer of the truck. It is known, for example, from GB-A-2 136 362 to use the deflector as a sun shield.
The solutions known from the prior art do not permit to create air efficient insulation, in order to prevent the cabin of the driver to reach air uncomfortable temperature. Indeed, the air trapped in the space delimited between the roof and the deflector panel eventually heats up and therefore creates a hot air bubble just on top of the roof.
It is desirable to provide a new truck having a cabin adapted to provide air efficient sun insulation when the truck is parked, especially with its engine shut down.
To this end, the invention concerns, according to air aspect thereof, a truck having a cabin, said cabin having a roof and air aerodynamic roof deflector panel mounted on said roof and covering at least partly said roof. The panel comprises at least a member movable between a first position and a second position. This truck is characterized in that, in the second position, an air passage is created in front of the space, whereas in the first position, the air passage is closed or substantially closed.
Thanks to an aspect of the invention, the space on top of the cabin of the truck is well insulated from the sun thanks to the panel and to the ability given to air to circulate between the panel and the roof of the cabin when the movable member is in its second position, thereby limiting the temperature of the air in contact with the roof of the cabin. In the meaning of this invention, the front of a part or a volume is a portion of a part or a volume oriented towards the front side of the vehicle that is the side of the vehicle which moves ahead of the other parts when the vehicle travels in normal road conditions. A first part or volume is in trout of a second part or volume when the first part or volume is ahead of the second part or volume when the vehicle travels in normal road conditions.
According to further aspects of the invention which are advantageous but not compulsory, such a truck may incorporate one or several of the following features:                In the first position of the movable member, a front edge of said member, extending in a substantially horizontal direction, is close to or in contact with the roof, and in the second position, this front edge is remote from the roof, at a distance of the roof larger than 30 mm, preferably larger than 60 mm.        In the second position of the movable member, at least one side edge of this member is remote from a lateral surface of the cabin.        The distance between the front edge of the movable member and the roof is adjustable.        The truck comprises means, in particular fans, to initiate convection heat exchanges between air and the roof of the cabin in the space extending between the roof and the panel.        The truck comprises means to seal a junction zone between the member and the roof of the cabin.        The means to seal the junction comprise a sealing gasket and/or compressible foam adapted to lay in a sealed manner between, on the one hand, the front edge and/or a side edge of the member and, on the other hand, the roof of the cabin.        
The movable member can be moved into air intermediate position, in which the distance between the front edge of the movable member and the roof is lower than in the second position.                The movable member is the totality of the panel.        The truck comprises sliders and at least one actuator adapted to move the panel in translation along the sliders from its first position to its second position.        The truck comprises one or several actuators adapted to elevate the panel relative to the roof of the cabin and to move the panel to air advanced position relative to the roof of the cabin.        The panel is mounted on the roof of the cabin thanks to articulated arms, whereas it comprises at least one actuator adapted to simultaneously elevate the panel relative to the roof of the cabin and move the panel forward relative to the roof of the cabin.        The or each movable member is a flap consisting in or comprising a portion of the panel.        The truck comprises several flaps mounted in the vicinity of the front side of the cabin and in the vicinity of lateral surfaces of the cabin.        The truck comprises means to move the movable member with respect to the roof on the basis of parameters representing the operating state of the truck and/or a temperature measured in the cabin, in the space extending between the panel and the roof and/or in the ambient air.        
The invention also relates according to air aspect thereof to a method for controlling a truck having a cabin, said cabin having a roof and air aerodynamic roof deflector panel mounted on said roof and substantially parallel to said roof. This method comprises a step consisting in or comprising moving least a portion of the panel from a first position to a second position. According to air aspect of the invention, in the second position, an air passage is created in front of a space extending between the roof and the panel whereas, in the first position, the air passage is closed or substantially closed.
According to further aspects of the invention which are advantageous but not compulsory, such a method may incorporate one or several of the following features:                The step of moving said portion of the panel from its first position to its second position is implemented when air internal combustion engine of the truck is shut down and/or when a park brake is activated.        The step of moving said portion of the panel from its first position to its second position is implemented when a temperature, measured in the cabin, in a space extending between the panel and the roof and/or in the ambient air, reaches a threshold value.        